UK: Fault in NHS Covid app meant thousands at risk did not quarantine

Fault in NHS Covid app meant thousands at risk did not quarantine Error meant users spent much longer next to infectious person before self-isolating Alex Hern the Guardian

A code error in the NHS Covid-19 app meant users had to be next to a highly infectious patient for five times as long as the NHS had decided was risky before being instructed to self-isolate, the Guardian has learned.

The oversight in the app meant thousands of people were told they did not need to quarantine when they were in fact at risk of spreading coronavirus.

The problem was only discovered last week, when software engineers rewrote how the app decides who needs to isolate and discovered it had been relying on faulty maths since its launch in September. According to the Sunday Times, which reported on the flaw, a source said the fault meant that a “shockingly low” number of warnings were issued. ...

A Department for Health and Social Care (DHSC) spokesperson said the England and Wales version was “the only app in the world using the latest Google-Apple technology to better gauge distance to identify those most at risk, and is deemed ‘excellent’ by international standards. ...